Dense antenna networks such as those found in RFID-enabled (Radio Frequency Identification-enabled) shelving, bins, cabinets, product displays, or rack systems are often characterized by hundreds or even thousands of individual RF (Radio Frequency) antennas. These antennas are typically connected directly or indirectly (through switches or switch networks) to RF transmitter-receivers often referred to as “RFID readers” which modulate an RF carrier wave to communicate with RFID transponders in the environment located around the antennas, and which further may demodulate responsive signals received from the transponders. In order to reduce the number of readers servicing a large antenna network, it is known to use complex switching schemes which are capable of connecting one of the many antennas to the reader.
FIG. 1 is a schematic illustrating a typical prior art approach. Individual RFID antennas 100 are connected to a central common RF communications cable 105 using simple switches or relays 110. Over the common cable, the antennas are driven from an RFID reader 120 which generates outgoing and interprets incoming RF signals, referred to herein as “traffic signals”. The reader is controlled by commands received from a computer 130. To initiate communication with transponders 140 within the read range of a particular antenna, the computer 130 selects an antenna and sends the identity of the selected antenna to the switch controller 150, which in turn activates the selected antenna using a control line 115 coupled between the switch controller 150 and the antenna's associated relay 110. The other antennas are deactivated over their respective control lines. The computer 130 then instructs the reader 120 to collect the required information, and the results from the reader 120 are returned to the computer 130 and associated with the active antenna.